The detection, identification and quantification of target molecules in a sample has a wide variety of applications in many fields. For example, in medical diagnostics it is desirable to be able to screen bodily fluids, such as blood, for the presence of particular targets that may be indicative of a disease or disorder. In other areas, such as bioterror and environmental remediation, it is important to be able to identify the presence of toxic compounds or infectious agents in the environment.
Sensors for identifying targets of interest may be based on or related to transistor principles used for electronic devices in integrated circuits. One such sensor is described in U.S. Pat. No. 5,466,348, which is incorporated by reference herein in its entirety.